The present invention relates to a fuel supply apparatus including a sub tank inside a main tank to supply a fuel inside the sub tank to an engine.
Conventionally, among fuel supply apparatuses applied to vehicles such as automobiles, there has been a type in which a sub tank is placed inside a main tank that stores a fuel. A sub tank is a fuel storage vessel, a cross section of which is sufficiently smaller than a main tank, and it has a fuel supply pump inside and has a jet pump at a position that connects the inside and the outside. A fuel supply pump is for taking in the fuel that is stored inside a sub tank and supplying this to an engine. The jet pump is for spraying a part of the fuel from a jet pump nozzle, and sucking a fuel stored in a main tank into the sub tank by using a negative pressure generated thereby.
According to a fuel supply apparatus as noted above, when the fuel supply pump is operated, the fuel inside the main tank is sucked into the sub tank by the jet pump, such that the fuel is always stored inside the sub tank. Accordingly, even when a liquid level of the fuel stored inside the main tank is temporarily lowered as a vehicle is inclined or due to centrifugal force on the vehicle, it becomes possible to assuredly supply the fuel stored inside the sub tank to an engine.
Incidentally, it is common that the jet pump described above is constituted at a bottom part of the sub tank in order to assuredly suck the fuel inside the main tank into the sub tank even when only a small amount of the fuel remains. Because of this, when the fuel supply apparatus is assembled, before the fuel supply pump is supported inside the sub tank, a channel for supplying a partial fuel ejected from the fuel supply pump must be connected to the jet pump nozzle which is provided on a bottom part of the sub tank. This operation must be performed inside an inner recess of the sub tank, and it becomes an issue that markedly complicates an assembly operation of the fuel supply apparatus.
The present invention has been made in view of the foregoing, and an object of the invention is to provide a fuel supply apparatus that simplifies an assembly operation thereof.
Further objects and advantages of the invention will be apparent from the following description of the invention.
In the present invention, a fuel supply apparatus has a sub tank inside a main tank that stores a fuel, and a jet pump nozzle inside this sub tank. A part of the fuel taken in from the sub tank to be supplied to an engine is sprayed from a tip of the jet pump nozzle. The fuel inside the main tank is drawn into the sub tank from a bottom part by a negative pressure caused by the jet pump nozzle. Holding means for holding the jet pump nozzle in the sub tank is provided between the sub tank and the jet pump nozzle when the jet pump nozzle is inserted into the sub tank.
It is preferable for the holding means to be provided on at least one of the sub tank and the jet pump nozzle, and to include an elastic engagement part that engages one of the sub tank and the jet pump nozzle elastically. Also, it is preferable that the holding means includes a position regulating part that regulates the position of the jet pump nozzle with respect to the sub tank.
When a tip of the jet pump nozzle is exposed to an outside of the sub tank, a recess portion is preferably formed on an outer surface of the sub tank, and the tip of the jet pump nozzle is positioned in the recess portion. A seal member for sealing a fuel supply channel is provided in the jet pump nozzle.